dep: pull in latest go event bus

There was a panic in the old version.

go.mod

@@ -62,6 +62,7 @@ require (
 	github.com/jbenet/go-random-files v0.0.0-20190219210431-31b3f20ebded
 	github.com/jbenet/go-temp-err-catcher v0.0.0-20150120210811-aac704a3f4f2
 	github.com/jbenet/goprocess v0.1.3
+	github.com/libp2p/go-eventbus v0.0.3 // indirect
 	github.com/libp2p/go-libp2p v0.2.0
 	github.com/libp2p/go-libp2p-autonat-svc v0.1.0
 	github.com/libp2p/go-libp2p-circuit v0.1.0
@@ -111,7 +112,6 @@ require (
 	go4.org v0.0.0-20190313082347-94abd6928b1d // indirect
 	golang.org/x/sync v0.0.0-20190423024810-112230192c58 // indirect
 	golang.org/x/sys v0.0.0-20190626221950-04f50cda93cb
-	google.golang.org/appengine v1.4.0 // indirect
 	gopkg.in/cheggaaa/pb.v1 v1.0.28
 	gotest.tools/gotestsum v0.3.4
 )

go.sum

@@ -374,6 +374,8 @@ github.com/libp2p/go-conn-security-multistream v0.1.0 h1:aqGmto+ttL/uJgX0JtQI0tD
 github.com/libp2p/go-conn-security-multistream v0.1.0/go.mod h1:aw6eD7LOsHEX7+2hJkDxw1MteijaVcI+/eP2/x3J1xc=
 github.com/libp2p/go-eventbus v0.0.2 h1:L9eslON8FjFBJlyUs9fyEZKnxSqZd2AMDUNldPrqmZI=
 github.com/libp2p/go-eventbus v0.0.2/go.mod h1:Hr/yGlwxA/stuLnpMiu82lpNKpvRy3EaJxPu40XYOwk=
+github.com/libp2p/go-eventbus v0.0.3 h1:4sB0NrwnWr6qGeq2RWUp/JG1wNajf6gyILInId72hrw=
+github.com/libp2p/go-eventbus v0.0.3/go.mod h1:Hr/yGlwxA/stuLnpMiu82lpNKpvRy3EaJxPu40XYOwk=
 github.com/libp2p/go-flow-metrics v0.0.1 h1:0gxuFd2GuK7IIP5pKljLwps6TvcuYgvG7Atqi3INF5s=
 github.com/libp2p/go-flow-metrics v0.0.1/go.mod h1:Iv1GH0sG8DtYN3SVJ2eG221wMiNpZxBdp967ls1g+k8=
 github.com/libp2p/go-libp2p v0.0.2/go.mod h1:Qu8bWqFXiocPloabFGUcVG4kk94fLvfC8mWTDdFC9wE=